Stringed musical instrument body construction

ABSTRACT

A structure for the soundbox of a stringed musical instrument is disclosed wherein the peripheral side wall is formed with channels at its bottom and top edges. The bottom and top of the body of the stringed instrument have flange portions on their peripheral edges which engage the channels on the side wall to form the soundbox. Mechanical and/or chemical means for strengthening the coupling between top and bottom flange portions of the body and the side wall channels is provided.

United States Patent [1 1 Dopera Filed:

STRINGED MUSICAL INSTRUMENT BODY CONSTRUCTION Inventor: RudolphDope-2,1410 Gaylord St., Long Beach, Calif. 90813 Oct. 23, 1970 Appl.No.: 83,310

US. Cl. ..84/291, 84/267, 29/ 169.5 Int. Cl. ..Gl0d 3/00 Field of Search..84/290, 291, 292, 296, 267;

29/ 169.5, DIG. 47

References Cited UNITED STATES PATENTS Springer ..84/292 Dopyera.....84/292 Maccaferri ..84/29l Dopera ..84/292 X p 51 Mar. 27, 1973FOREIGN PATENTS OR APPLICATIONS 4,924 2/1932 Australia ..84/291 PrimaryExaminer-Richard B, Wilkinson Assistant Examiner.lohn F. GonzalesAttorney-Jones & Lockwood [57] ABSTRACT A structure for the soundbox ofa stringed musical instrument is disclosed wherein the peripheral sidewall is formed with channels at its bottom and top edges. The bottom andtop of the body of the stringed instrument have flange portions on theirperipheral edges which engage the channels on the side wall to form thesoundbox. Mechanical and/or chemical means for strengthening thecoupling between top and bottom flange portions of the body and the sidewall channels is provided.

PATENTEDMARZ 7 I975 INVE/V r0? RUDOLPH DOPE RA A TTOR/VEYS STRINGEDMUSICAL INSTRUMENT BODY CONSTRUCTION BACKGROUND OF THE INVENTION Thisinvention relates to improved methods of designing and perfecting thesoundbox or body of a stringed musical instrument and refers, inparticular, to the fabrication of a guitar made of an extrudablematerial such as metal, thermoplastic resins, or the like.

Makers of stringed musical instruments usually are quite particular inselecting stock to make their instruments. Such instruments haveheretofore been practically universally constructed of wood componentssuitably formed shaped and glued together. Despite careful workmanship,stresses and strains develop in various parts of these instruments as aresult of changes in weather conditions and the like, which causewarping and shape distortions. Consequently, these conditions affect thetone and quality of these instruments.

Efforts have been made to alleviate these problems by using metals,e.g., steel, aluminum and the like to construct such instruments, andfor many years such stringed instruments have been made by duplicatingin metal the construction techniques used for wood. Thus, complicatedwelding and soldering procedures have developed which make themanufacture of such instruments difficult, resulting in high costs.Although aluminum is at present a preferred material for theseinstruments, the difficulties involved in welding this metal haseffectively precluded its use.

SUMMARY OF THE INVENTION- It is an object of this invention to provide anew and useful method and apparatus for constructing the soundbox orbody of a stringed musical instrument which is simple and inexpensive.

Another object of this invention is to provide a side wall constructionfor a soundbox which facilitates construction of the instrument, whileat the same time providing a novel and decorative appearance.

More particularly, the object of this invention is'to provide a newmethod and apparatus to construct the body of a guitar which is simplein operation and does not require any elaborate pre-shaping or weldingto join the top and bottom portions of the guitar to the peripheral sideportion thereof.

According to this invention, a peripheral side piece for the soundbox ofa stringed instrument is fabricated, as by extrusion, from a suitablematerial, which may be a thermoplastic resin of selected type, a metal,preferably aluminum, or like material so that it has channels at its topand bottom ends. The side piece is then formed to the desired soundboxshape so that top and bottom portions of the body of the instrument,which are fabricated to have appropriate shapes and include flanges,will fit the channels of the peripheral side piece. The structure soobtained can be further strengthened by chemical bonding using an epoxyor other suitable adhesive, and/or by mechanical means, such as rivetsor the like. The side piece is preferably formed with a plurality ofgrooves extending parallel to the upper and lower edges of the sidewall, these grooves serving to strengthen the wall and to providereceptacles for suitable decorative material.

2 BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and additionalobjects, features and advantages of the invention will be apparent fromthe following description and from the claims appended thereto, taken inconjunction with the accompanying drawings, in which:

FIG. 1 is an exploded view of a soundbox for a stringed musical.instrument made according to the teachings of the present invention, butwith the strings and complemental parts omitted for clarity;

FIG. 2 is a cross-section of the side wall of FIG. 1 taken along line2-2;

FIG. 3 is a cross-section similar to that of FIG. 2, but showing anotherembodiment of the peripheral side wall of the soundbox;

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings,where like numerals show the same parts in each figure, and firstparticularly to FIG. 1, the peripheral side wall of a musical instrumentembodying the present invention .is indicated generally at 8..Forpurposes of this description, the instrument will be described as aguitar, but it will be understood that other stringed instruments can besimilarly constructed. The peripheral side wall 8 is formed from anelongated sheet 10 of a metal, preferably aluminum, a plastic material,or the like, extruded in the desired cross-sectional configuration. Theextrusion has a channel 12 at the top edge 14 thereof, as may be seen inFIG. 2, and a similar channel 16 at 7 the bottom edge 18. Channel 12 isformed by two walls,

as may be seen in FIG. 2, an outer wall 20 and an inner wall 22. Thesheet from which the side wall is formed is preferably of uniformthickness, being extruded through a die in known manner to form thedesired cross-sectional shape to be given to the side wall. The openends of the elongatedsheet so formed are then brought together whileshaping the sheet against a suitable forming block (not shown) to formthe desired guitar body'outline, as illustrated in FIG. 1, and the endsof the sheet are secured together at 24 as by welding or some othersuitable means. The forming block will preferably be of steel, groovedand shaped to the exact size and contour of theinstrument being formed.As further illustrated in FIG. 2, the cross-sectional shape of theperipheral side wall 8 in one embodiment may be of uniform thickness,providing a flat, smooth outer surface. It will also be seen in FIG. 2that thechannel 16 at the bottom edge 18 of the side wall is formed bytwo parallel, spaced walls, an outer wall 26 and an inner wall 28. Asillustrated, the inner walls of both the upper and lower channels areformed on inwardly ofiset shoulders 30 and 32, whereby the outer wallsremain flush with the outer surface of the wall, and both channelsextend at a uniform depth around the corresponding edge of wall 8.

FIG. 3 shows a cross-section of a peripheral side wall similar to thatof FIG. 2, but indicating another embodiment of the invention. Themodified side wall 36 includes a top edge channel 12 formed by an outerwall and an inner wall 22 and a bottom edge channel 16 formed by anouter wall 26 and an inner wall 28. The peripheral side wall 36 in thisembodiment is extruded with a different cross-sectional shape, so thatthe exterior surface of the wall is provided with a plurality of grooves44 and ridges 46 extending the length of the sheet from which the guitarbody walls are formed. The interior surface of the wall is thus formedwith cor responding ribs 47 which serve to reinforce the wall. Thegrooves are adapted to receive a decorative material, such as thedecorative inlay strips described and claimed in copending applicationSer. No. 3,107, filed .Ian. 15, 1970, and entitled Decorative Trim,

which is a continuation-in-part of application Ser. No.

776,919, filed Nov. 19, 1968, now abandoned. These decorative inlaystrips may take many forms, as set forth in detail in the said copendingapplication, but in one form may comprise an extruded conduit oftransparent or translucent damage-resistant material. The conduitpreferably will have at least one inner bore of any suitablecross-sectional shape, and is adapted to receive a decorative materialsuch as twisted fibers, metallic cords, ribbons, braids, or othermaterials of selected colors or color combinations. In the illustrationof FIG. 3, the depth of grooves 44 is sufficient to hold the decorativeinserts so that their upper surfaces will be flush with the outer wallsurface; further, the grooves are slightly dovetailed so as to firmlyhold the decorative inserts in place.

The grooves 44 and ridges 46 are formed in the sheet from which theguitar body is to be formed, the sheet being extruded from asuitably-shaped die, and the decorative inserts are placed in thegrooves by sliding them in from one end of the sheet. If desired, theinserts may be glued in place, or otherwise fastened; however, thedovetail arrangement is generally sufi'rcient to hold the inserts.Thereafter, the extruded sheet may be shaped around a suitable formingblock to form the peripheral side wall contours shown in FIG. 1. It willbe apparent that in so forming the sheet, care must be taken to reducethe amount of distortion of the grooves around the curved areas of theside wall, but the use of a grooved forming block facilitates this. Theshaping of the side wall also shapes the decorative material, with thebends in the sheet serving to close the dovetailed walls of the groovesagainst the inserts to hold them tightly in place.

Referring again to FIG. 1, there is shown in perspective view the topportion 48 of the guitar body which has a depending flange 51 adapted tomate with the channel formed in the upper edge of the side wall 8 informing the guitar soundbox. The top portion is generally flat, althoughother configurations, including various curvatures, are also possible,and is provided, in conventional manner, with a sound opening 50. Alsoshown in the exploded view of FIG. 1 is a perspective view of the bottomportion 52 of the guitar body, this portion including an upstandingperipheral flange 53 adapted to mate with the channel formed in thebottom edge 18 of the peripheral side wall 8 to complete formation ofthe soundbox. Again, the bottom portion may be flat or curved in knownmanner to provide the desired instrument shape. As with the side wall,the top and bottom portions of the guitar body can be made of a metallicmaterial, preferably aluminum, a plastic material, or the like, andgenerally will be stamped out of a sheet of the selected material. Theperipheral side wall 8, top portion 48, and the bottom portion 52 formthe body, or soundbox, when they are joined together.

FIG. 4 is a partial cross-section of the top portion 48 taken along line4-4 of FIG. -1 wherein numeral 54 indicates the upper surface,or face,of the top portion and numeral 51 shows the depending flange which isshaped to fit in the upper channel 12 of the peripheral side wall 8. Thethickness of the top portion is shown to be generally uniform, althoughvariations of thickness are also possible. A small lip 60 of the topportion 48 extends beyond the flange 51 by a distance equal to thethickness of the outer wall 20 of the channel, so that the top portion48 will completely cover the side wall when the soundbox has beenassembled. The bottom portion 52 has a structure similar to that of thetop portion and is thus not shown in detail.

FIG. 5 is a vertical cross-section of an assembled, modified guitar bodysoundbox, having a top portion 64, a bottom portion 66, and a peripheralside wall 68, the three elements being in engagement with one another toform the guitar body. The top portion 64 and the bottom portion 66 are,in this embodiment, formed with a downtumed edge 70 and an upturned edge72, respectively, the edges providing flanges to engage the channels 12and 16 in the top and bottom edges of the peripheral side wall. Asshown, the flanges 70 and 72 so formed do not have an outwardlyextending lip to cover the thickness of the outer wall of the channelson the peripheral side wall. It will be apparent, however, that theflange arrangement of FIG. 4 can be used with the side wall 68, ifdesired.

The peripheral side wall 68 is provided with a plurality of paralleldepressions 74 extending along its periphery, which are adapted toreceive a decorative inlay strip material of the type described above.These depressions are formed, as before, during extrusion of the sidewall, but in this embodiment the decorative strips may be placed eitherbefore or after the soundbox has been formed. The depressions 74 may begenerally rectangular in cross-section, or may be of other suitableshape. The interior surface of wall 68 is formed with a plurality ofribs 75 corresponding to the depressions 74, these ribs serving toreinforce and strengthen the side wall.

To assemble the soundbox of any of the disclosed embodiments, theflanges of the top and bottom portions are fitted into the respectivetop edge and bottom edge channels of the side wall portion. Although thesize of the channels is such that the flanges are held tightly in placeby friction, it has been found that because the materials used in makingthe soundbox, a tightly fitting joint will not hold; therefore, thejoint should be further strengthened by using an epoxy glue in thechannels before fitting the flanges therein. The

similar fasteners 76, 78, 80, and 82 spaced around the periphery of thesoundbox, the rivets passing through both walls of the channel andthroughtheflange, as illustrated.

Thus, there has been described and illustrated a new and improvedstructure for a guitar body, wherein the side wall is formed from anextrusion having a unique configuration which facilitates constructionof the guitar, improves its strength, and provides a novel anddecorative appearance. The use of channels on the top and bottom edgesof the side wall together with flanged top and bottom covers permitsquick assembly of the guitar, for the flanges assure proper fit andalignment of parts. Further, this construction permits the use ofrivets, epoxy resin glue, welds or other fasteners which assure a strongand durable soundbox that will withstand long and hard use. The form ofthe side walls is such as to accommodate the use of extrusion processesin the manufacture of the guitar, thus minimizing the cost of making theguitar, and permitting the use of the grooved structures illustrated inthe various embodiments of the invention. These grooves serve not onlyto receive decorative inlay materials, as discussed above, to provide anew and striking appearance in the completed guitar, but the shape ofthe grooves is also such as to provide added strength and rigidity tothe guitar, for in making exterior grooves, there are formedcorresponding interior ribs. The extrusion process facilitates makingthe instrument of not only metals such as aluminum, but thermoplasticresins of various types.

Although the invention has been shown and described in terms of specificembodiments thereof, it will be understood that various changes may bemade from the construction disclosed without deviating from the spiritand scope of the invention as set forthin the following claims.

I claim: a

1. In a soundbox for a stringed musical instrument having a bottomportion having a first flange along its periphery and facing generallyvertically upward; a top portion of shape matching the bottom portion,and having a second flange along its periphery facing generallyvertically downward; a peripheral side wall of shape matching the bottomand top portions and having two edges, an upper edge and a lower edge,the lower edge of the side wall having a first channel adapted toreceive said first flange to form a first joint and the upper edge ofthe side wall having a second channel adapted to receive said secondflange to form a second joint, whereby the soundbox is formed; theimprovement comprising:

a plurality of parallel, longitudinally extending decorative materialreceiving grooves on the outer surface and extending the length of saidperipheral side wall, and corresponding parallel, longitudinallyextending ribs on the peripheral inner surface of said side wall, saidribs serving to reinforce 5 said side wall.

2. The soundbox of claim 1, wherein said grooves are dovetailed in orderto receive and hold decorative inlay strips correspondingly dovetailed.

3. A method of making a soundbox for a stringed 10 musical instrumentwhich comprises the steps of:

a. extruding an elongated sheet having an upper and a lower edge andfirst and second ends, while for'min a first channel in said upper edge,a secon channel in said lower edge, a plurality of grooves in onesurface of said sheet extending the lengthof said sheet, and a pluralityof ribs in the other surface of said sheet extending the length of saidsheet, and said grooves and ribs being parallel to said upper and loweredges and said grooves being adapted to receive decorative inlay strips;

b. locating decorative inlay strips in said grooves;

c. wrapping said sheet around a forming block, said block being shapedto the desired'contour of a sidewall for said soundbox and havinggrooves on its peripheral wall surface corresponding to the ribs formedin the inner surface of said sheet, the ribs on said sheet fitting intothe grooves on said block as said sheet is wrapped around said block,

d. securing the two ends of the sheet material together to retain theshape of said side wall;

. e. forming a top portion of said soundbox, said top portion beingformed with a flange extending generally vertically downward;

f. forming a bottom portion for said soundbox, said bottom portion beingformed with a flange extend ing generally vertically upward;

g. fitting the downwardly extending flange of the top portion into thefirst channel of the peripheral side wall to form a first joint;

h. Fitting the upwardly extending flange on the bottom portion into thesecond channel of the peripheral side wall to form a second joint,thereby completing the assembly of said soundbox.

4. The method of claim 3, which further comprises second joints tosecure said top and bottom portions to placing rivets at spacedlocations through said first and

1. In a soundbox for a stringed musical instrument having a bottom portion having a first flange along its periphery and facing generally vertically upward; a top portion of shape matching the bottom portion, and having a second flange along its periphery facing generally vertically downward; a peripheral side wall of shape matching the bottom and top portions and having two edges, an upper edge and a lower edge, the lower edge of the side wall having a first channel adapted to receive said first flange to form a first joint and the upper edge of the side wall having a second channel adapted to receive said second flange to form a second joint, whereby the soundbox is formed; the improvement comprising: a plurality of parallel, longitudinally extending decorative material receiving grooves on the outer surface and extending the length of said peripheral side wall, and corresponding parallel, longitudinally extending ribs on the peripheral inner surface of said side wall, said ribs serving to reinforce said side wall.
 2. The soundbox of claim 1, wherein said grooves are dovetailed in order to receive and hold decorative inlay strips correspondingly dovetailed.
 3. A method of making a soundbox for a stringed musical instrument which comprises the steps of: a. extruding an elongated sheet having an upper and a lower edge and first and second ends, while forming a first channel in said upper edge, a second channel in said lower edge, a plurality of grooves in one surface of said sheet extending the length of said sheet, and a plurality of ribs in the other surface of said sheet extending the length of said sheet, and said grooves and ribs being parallel to said upper and lower edges and said grooves being adapted to receive decorative inlay strips; b. locating decorative inlay strips in said grooves; c. wrapping said sheet around a forming block, said block being shaped to the desired contour of a sidewall for said soundbox and having grooves on its peripheral wall surface corresponding to the ribs formed in the inner surface of said sheet, the ribs on said sheet fitting into the grooves on said block as said sheet is wrapped around said block, d. securing the two ends of the sheet material together to retain the shape of said side wall; e. forming a top portion of said soundbox, said top portion being formed with a flange extending generally vertically downward; f. forming a bottom portion for said soundbox, said bottom portion being formed with a flange extending generally vertically upward; g. fitting the downwardly extending flange of the top portion into the first channel of the peripheral side wall to form a first joint; h. Fitting the upwardly extending flange on the bottom portion into the second channel of the peripheral side wall to form a second joint, thereby completing the assembly of said soundbox.
 4. The method of claim 3, which further comprises placing rivets at spaced locations through said first and second joints to secure said top and bottom portions to said peripheral side wall.
 5. The method of claim 4, which further comprises applying an epoxy resin to the first and second flanges and to the first and second channels before fitting the flanges into the respective channels to form the first and second joints. 